1. Field of the Invention
This invention relates generally to Voice Over Internet Protocol (VoIP) and long distance carriers, Internet Service Providers (ISPs), and information content delivery services/providers and long distance carriers. More particularly, it relates to 911 location services for the telecommunication industry.
2. Background of Related Art
911 is a phone number widely recognized as an emergency phone number that is used by emergency dispatch personnel, among other things, to determine a location of a caller. Enhanced 911 (E911) is defined by the transmission of callback number and location information. E911 may be implemented for landline and/or mobile devices.
Some Public Safety Access Points (PSAPs) are not enhanced, and thus do not receive the callback or location information from any phone, landline or mobile.
Voice Over IP (VoIP) is a technology that has been developed as an alternative telephony technology to the conventional telephony service (e.g. PSTN). VoIP takes advantage of high speed Internet data switched networks, and is able to provide low cost telephony services to end users. VoIP technology emulates a phone call, but instead of using a circuit based system such as the telephone network, utilizes packetized data transmission techniques most notably implemented in the Internet.
Voice Over IP is not a single technology, but rather four distinctive applications targeted at distinct market segments in either static, portable, or mobile environments. A first application is the use of VoIP technology with cable and digital subscriber line (DSL), often deployed in static configurations in which the end user stays at a fixed location and uses the standard North American Numbering Plan. Examples of this type service include residential line replacement using cable or DSL connections. Another frequent application is an enterprise use of VoIP technology, usually deployed in static configurations with occasional portability, allowing the end user to easily move his telephony connection anywhere within the enterprise campus. A third application is the use of VoIP with an Internet Service Provider (ISP), usually provided as a highly portable telephony configuration which allows the end user to establish a telecommunications connection wherever they can obtain an internet-based connection to their ISP provider. A last application is the use of VoIP with a Wireless Fidelity (WiFi) network. This is a mobile telephony configuration that allows the end user to take a home-based telephony connection and roam within an interconnected WiFi network, much like cellular technologies allow today.
As VoIP service providers begin to offer VoIP packet based telephony service to the general public as a replacement to conventional switched telephone networks, one key service related issue has been identified in the need to support the ability to determine a caller's location when they dial “911” using a VoIP device. The FCC in the United States has mandated E911 for wireless devices, but not (yet) for VoIP. The VoIP industry, with NENA encouragement, is currently making efforts to voluntarily comply. Moreover, such 911 services become even more important as additional mobility options become available for VoIP terminals, e.g., mobile VoIP phones.
There are at least three VoIP scenarios that require E911 service:                1. The VoIP device is physically connected to a static data cable at a “home” address.        2. The VoIP device is physically connected to a data cable at a location different than its “home” address. For instance, a laptop computer device utilized away from home as a VoIP communication device would be a VoIP ‘visitor’ device as described by this scenario.        3. The VoIP device is wirelesses, physically disconnected from any data cable. In this situation, the VoIP device connects to the VoIP network via cellular or WiFi technology.        
A VoIP gateway is a gateway that bridges a VoIP network (i.e., a packet switched voice service) with a conventional public switched telephone network (PSTN) (i.e., a circuit switched voice service). A major advantage enjoyed by users of a VoIP network is often referred to as “long distance bypassing”. To accomplish a suitable VoIP network, a VoIP provider establishes VoIP gateways throughout a region or country of interest. Each VoIP gateway is connected to a local PSTN. This allows VoIP customers to make long distance calls via the VoIP network, which then route the call to a desired destination using the local circuit at the local gateway.
Conventional VoIP voice gateways are typically located in only a few places across the country. Thus, any 911 call originating in a city such as Miami, for example, may initially be routed to the public safety answer point (PSAP) in, e.g., Minneapolis if the VoIP gateway happens to be located in Minneapolis. Moreover, the call will not be “enhanced”. That is, it will not provide any location or callback information to the dispatcher.
Not all PSAPs support direct-dial administrative lines, many administrative lines are not answered 24 hours-a-day or during periods of heavy call volume, and administrative lines do not support the ability to automatically identify the location of a party dialing 911. Rather, the location of the caller is typically conveyed verbally or through alternative data entry methods that are not supported by all PSAPs. Furthermore, today's VoIP solutions for portable environments terminate calls to an administrative telephone lines at a Public Safety Answering Point (PSAP)—not directly to emergency operators. Thus, unlike 911 calls originating from a wireline or a mobile phones, 911 calls made from a device utilizing VoIP may be routed to an administrative line and are sometimes answered by a front desk receptionist or administrator instead of an actual emergency operator, wasting valuable seconds in the case of an emergency. In addition, existing solutions for 911 calls made on a VoIP network are frequently unable to determine the geographic location of the VoIP caller dialing 911. For example, if an individual is using a virtual private network to tunnel into a corporate server and make a VoIP call through that server, a 911 call will provide no location information unless manually entered before the call.
This problem has been partially resolved as described in FIG. 12, which shows a conventional architecture for providing 911 service to a VoIP device.
In particular, as shown in FIG. 12, a conventional architecture routes VoIP 911 calls to a designated PSAP. However, such architecture fails to provide “enhanced” service for VoIP devices.
In particular, Option 1 in FIG. 12 shows an IP device 250 utilizing VoIP protocols for voice communications dials 9-1-1. The VoIP device 250 is serviced by a VoIP switch 220 in the VoIP service provider's network. The VoIP switch 220 communicates with a Message Servicing Center (MSC) 230. Using a database that relates the devices callback number or IP address to the owner's address, the MSC 230 can determine which PSAP has jurisdiction for that address. The MSC 230 then communicates back to the VoIP switch 220 a 10-digit telephone number for that PSAP. The VoIP Switch 220 then converts the IP call to TDM and routes the call to the designated PSAP using the provided 10-digit number.
A primary challenge results from the fact that the E911 network is not directly accessible via the Public Switched Telephone Network (PSTN); Rather, all enhanced 911 calls must be routed via dedicated local voice trunks to a selective router that in turn routes the call to the PSAP. Calls that do arrive at the PSAP arrive without callback number or location information. Provision of location information to the PSAP via the PSTN also circumvents specific PSAP hardware (e.g., CAD, GIS) designed to facilitate dispatching of responders and tracking the location of the mobile caller.
There is a need for an architecture and methodology to allow VoIP users all features relating to E911 services enjoyed by non-VoIP users, e.g., call back phone number and location information provided to a public safety answer point (PSAP), and to do so both accurately and as quickly as possible. In emergency call situations, often seconds can mean the difference between life and death.